Synthesis and spectroscopic behaviour of metal complexes of meso-alkylidenyl carbaporphyrinoids and their expanded analogues

Treatment of meso-malonylidene-(m-benzi)porphyrin and meso-malonylidene-(m-benzi)pentaphyrin with Pd(II), Au(III), Ni(II) and Ag(I) afforded the corresponding metal complexes. The synthesized metal complexes were characterized by spectroscopy including single crystal X-ray, NMR and mass spectrometry. Most metal complexes were stable in solution. The metal complexes showed strong absorption in the near IR region.